Granted Patent
Utility
US 4,136,820 · App. 05/824,373
Automatic calling directory
Inventors:
Juan Martinez Collado, Enrique Leon
Patented Case
View Patent ↗
Granted: Jan 30, 1979
Filed: Aug 15, 1977
Inventors
Juan Martinez Collado
Enrique Leon
Assignee (at issue)
International Telephone and Telegraph Corporation
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.